• Cobalt chloride should be added to the ever growing list of contact urticants. This chemical is frequently used as a color indicator in provocative sweat testing. In this case, contact urticaria was probably nonimmunologic in origin. Since diphenhydramine and 48-80 (polymonine) block this reaction to cobalt chloride, vasoactive amines are at least partially responsible for the urticaria.
(Arch Dermatol 111:1610-1611, 1975)
Smith JD, Odom RB, Maibach HI. Contact Urticaria From Cobalt Chloride. Arch Dermatol. 1975;111(12):1610-1611. doi:10.1001/archderm.1975.01630240066013